What's wrong with this math calculation? $$3000 = ( p6300 + (1-p)2200 ) / 1.06
\\
3000 = p6300 + 2200 - p2200 / 1.06
\\
3000 = p4100 + 2200 / 1.06
\\
800 = p4100 / 1.06
\\
p4100 = 800\times1.06
\\
p4100 = 848
\\
p = 0.2068$$
The correct answer is $p=0.239.$
What mistake(s) have I made?
 A: As written, the first line says that $(1 - p) 2200$ has to be divided by $1.06$. However, you're messing that up in several ways in the subsequent steps.
Edit: in the comments the OP said the correct answer is 0.239. And, also mentioned in the comments, that indicates that the original question should be
$3000 = (p 6300 + (1 - p) 2200) / 1.06.$
A: 
I'm not good at solving an equation with brackets. Could you show it in a simple way, with steps, with the equation and values from my initial post?

Click here for the step-by-step working with the correct algebraic manipulations.
Regarding your suggested working, note that when you have parentheses in an arithmetic expression, first perform the operations within the innermost pair then keep working outwards. Also, note that:

*

*\begin{align}(a+b)c/d&=\frac{ac+bc}d\\\\&\ne ac+\frac{bc}d\end{align}
\begin{align}(3+5)2/7&=\frac{6+10}7\\\\&\ne 6+\frac{10}7\end{align}

*\begin{align}a+ b/c &= a+ \frac bc \\&\ne \frac{a+b}c\end{align}
\begin{align}2+ 3/7 &= 2+ \frac 37 \\&\ne \frac{5}7\end{align}
